The compound 4-biphenylacetic acid is known and its preparation described in the literature, F. Blicke, et al., J. Am. Chem. Soc., 65, 1725 (1943). U.S. Pat. No. 3,784,704 also discloses the preparation of 4-biphenylacetic acid, and its use in producing long lasting amelioration of pain in warm-blooded animals. French Pat. No. 7,166M, patented Feb. 23, 1970, reports that 4-biphenylacetic acid possesses anti-inflammatory, antipyretic and analgesic activity.
Substituted 4-biphenylacetic acids are described, for example, in Irish Pat. No. 56/65, Belgian Pat. No. 664,187 (11/19/65), South African Pat. No. 65/4206 (3/10/66), French Pat. No. 2401M (4/13/64). These references describe a variety of uses for the substituted 4-biphenylacetic acids. Esters of biphenylacetic acid are described by F. Blicke, et al. (J. Am. Chem. Soc. 65, 1725 (1943) as antispasmodics although the base compound is not indicated as having any activity. G. Cavallini et al. (II Farmaco Ed. Scient. II, 167 (1956) describe a number of substituted biphenylacetic acids as having anti-cholesterolemic activity.) Other references such as British Patent 034,534 (1/14/71) and T. Y. Shen, Chim. Ther. 2 (3) 459 (1957) describe a number of substituted biphenylacetic acids as anti-inflammatory agents. To the best of our knowledge, however, no art is known which is concerned with the use of 4-biphenylacetic acid to treat thrombotic conditions such as those resulting from the aggregation of blood platelets.
The aggregation of blood platelets is an important mechanism in thrombosis and as the degree of aggregation increases the tendency of thrombus formation also increases. We have shown that 4-biphenylacetic acid inhibits the aggregation of the blood platelets of warm-blooded animals. 4-Biphenylacetic acid can be useful, as an antithrombotic agent, in the treatment of well known thrombotic conditions resulting from platelet aggregation. Such conditions include, for example, arterial thrombosis, pulmonary embolism, cerebrovascular disease, rheumatic heart disease, myocardial infarction, thrombophelebitis or thromboembolic conditions which may develop spontaneously following surgery, trauma or disease processes such as coronary occlusion and congestive heart failure. It can be useful in reducing transient ischemic attacks of the brain and possibly the heart. 4-Biphenylacetic acid may also be useful extrinsically in preventing the clotting of shed and/or stored blood and it is contemplated that its use as a platelet inhibitor extends both in vivo and in vitro platelet aggregation inhibition. It may be merely added to blood in vitro to prevent or inhibit platelet aggregation.
Numerous platelet aggregation inhibitors are known such as those disclosed in U.S. Pat. Nos. 3,692,836; 3,721,738; 3,735,005; 3,794,729; 3,795,582; 3,809,753; 3,859,288; and 3,862,319.